The invention relates to a flat and thin accumulator device including a planar electrochemical cell with at least two laminar electrodes having opposite polarities, which electrodes are disposed on either one of the two sides of an electrolyte material, a moisture-proof envelope having two plane faces of a moisture-proof and electrically insulating material which faces are connected to each other in an airtight manner in a peripheral sealing area, and electrical contact means of the electrodes forming electrode terminals which run through said peripheral sealing area.
The invention finds its application in the manufacturing of electric batteries or rechargeable batteries applied to portable apparatus such as telephone terminals.
A flat accumulator device is already known from European patent published under no. EP 0 390 557 (inventor AUSTIN). This document describes a flat accumulator comprising a planar electrochemical cell, having at least two electrode plates having opposite polarities, an electrolyte-impregnated interposed material and electrode terminals connected to the electrode plates. The planar electrochemical cell is disposed between two foils of a flexible and moisture-proof insulating material, which are heat-sealed, in a sealing area around their periphery, so as to form an envelope enclosing said planar electrochemical cell. The electrode terminals run through the sealing area. These electrode terminals are tabs soldered to the electrode plates and the soldering area is situated inside the planar envelope and is enclosed in the electrolyte. In one of the embodiments of the accumulator, the upper foil of the planar envelope may have openings corresponding to the electrode terminals so as to allow of making contact with these electrode terminals from the exterior through these upper openings. Said openings occur in the peripheral sealing area of the upper and lower foils of the envelope.